As will be described in great detail below with respect to an illustrated prior-art power laser configuration, a power laser generally comprises an active element, i.e. the laser crystal itself, which is generally elongated and can be pumped in a conventional manner to generate a laser beam.
This beam is reflected between a pair of mirrors which are disposed at opposite ends of the laser crystal along the optical axis thereof and it is known to provide a passive Q switch in such systems between the output mirror and one end of the active element. The amplified light, i.e. the power laser output, emerges through the mirror at this end of the active element which is semi-reflecting.
The losses in such systems are high and, especially because of the presence of the passive Q switch which may not have negligible losses, it is desirable to minimize such losses.
Furthermore, the passive Q switch and other optical elements which may be used in such power laser applications have relatively low-damage thresholds and thus a tendency to be damaged by the output beam when traversed by the full intensity of the latter.